Not sure if 'air lock' is the correct phrase to use in this context but bear with me.
Mum has a 1.5 sink in the kitchen, see below for the way it's plumbed including the washing machine waste. The property (she's in a high rise) has good water pressure. I can put the tap on near full and the sink will keep on draining quite happily forever and a day. However, when the washing machine drains this happens:
1. For the first few seconds you can hear the water draining without issue.
2. The sound then stops. It's at this point you know it's no longer draining properly and the water is backing up.
3. The water then comes up into the main sink (how much can vary) and sometimes comes up into the half sink.
4. As soon as the washing machine stops draining, the backed up water in the sink/s clears.
I've concluded there can't simply be an issue with the plumbing being blocked 'behind the scenes' as the sink drains perfectly well minute in minute out with the tap on near full flow. It's almost like when the washing machine starts to drain, it's pumping the water at such a rate as to cause some sort of air lock? Because when it stops pumping, the backed up water drains away immediately.
For info, the shower tray in her shower room slow drains. We're getting that replaced and the plumber said the flats are known for slow draining trays, especially as the years go by and the plumbing in the main duct gets ever older. He said he can resolve the slow draining tray (and has in other flats) by replacing some of the pipework in the main duct. He said he can check the kitchen side of things as well, however given the sink itself drains ok, he's not sure if changing the pipework that side will resolve things.
Any thoughts? Mum goes into a slight panic when using the machine as the water can sometimes come up the sink to quite a degree!
Mum has a 1.5 sink in the kitchen, see below for the way it's plumbed including the washing machine waste. The property (she's in a high rise) has good water pressure. I can put the tap on near full and the sink will keep on draining quite happily forever and a day. However, when the washing machine drains this happens:
1. For the first few seconds you can hear the water draining without issue.
2. The sound then stops. It's at this point you know it's no longer draining properly and the water is backing up.
3. The water then comes up into the main sink (how much can vary) and sometimes comes up into the half sink.
4. As soon as the washing machine stops draining, the backed up water in the sink/s clears.
I've concluded there can't simply be an issue with the plumbing being blocked 'behind the scenes' as the sink drains perfectly well minute in minute out with the tap on near full flow. It's almost like when the washing machine starts to drain, it's pumping the water at such a rate as to cause some sort of air lock? Because when it stops pumping, the backed up water drains away immediately.
For info, the shower tray in her shower room slow drains. We're getting that replaced and the plumber said the flats are known for slow draining trays, especially as the years go by and the plumbing in the main duct gets ever older. He said he can resolve the slow draining tray (and has in other flats) by replacing some of the pipework in the main duct. He said he can check the kitchen side of things as well, however given the sink itself drains ok, he's not sure if changing the pipework that side will resolve things.
Any thoughts? Mum goes into a slight panic when using the machine as the water can sometimes come up the sink to quite a degree!